PHOENIX - Arizona managing partner Ken Kendrick was beside himself with joy when he introduced Wally Backman as the Diamondbacks' new manager. Kendrick waved a baseball card from Backman's playing days, with a photo on it of the scrappy player taking out a catcher at home plate.

"It probably tells you all you need to know about this guy as a player," Kendrick said at the time.

Apparently, though, there was much more to know about Backman the person.

Just four days later, a far more serious Kendrick sat in the same Arizona clubhouse Friday and announced that Backman had been dismissed because of evidence that arose from off-the-field problems, including two arrests and several financial problems.

The manager's job instead went to Bob Melvin, close friend of former Diamondbacks manager Bob Brenly and Arizona's bench coach when the team won its World Series title in 2001. Melvin had been one of three finalists for the Diamondbacks job after he was fired following two seasons as manager of the Seattle Mariners.

Before hiring Backman, the Diamondbacks didn't do any criminal or financial checks and were unaware of his problems until they were reported Tuesday in The New York Times.

"It's obviously a mistake on our part to have made a decision without having done the proper background work that could have been done, should have been done. I take full responsibility for that, and I'm very sorry," Kendrick said.

The Diamondbacks then hired a company to conduct an independent background check, managing partner Ken Kendrick said.

After their investigation, he added, "We determined that it wasn't in the Diamondbacks' interest or our fans' interest that Wally be our manager."

Backman was asked in his final interview whether there was anything in his past that the Diamondbacks should know, and he answered no, Kendrick said.

Kendrick declined to say what new information the club discovered, if any, but said, "Had we, at the time we made the decision, had all the facts that we ended up having, we would not have named Wally our manager."The episode led the Diamondbacks to institute mandatory background checks on all key hires - including Melvin.Backman never signed a contract and won't be compensated, Kendrick said. Calls to Backman were referred to his agent Terry Bross, who was out of his office and unavailable for comment.It would have been the first major league managing job for Backman, a second baseman who played 14 seasons and helped the New York Mets win the 1986 World Series.He was arrested in 2001 after a fight at his home involving his wife and one of her friends in Prineville, Ore. He pleaded guilty to misdemeanor harassment and was sentenced to 12 months' probation, ordered to undergo an anger management evaluation and donate $1,000 to the local Boys and Girls Club.Backman was also arrested, and later convicted, on a driving under the influence charge in Kennewick, Wash., in 2000.A judge in Benton County, Wash., has ordered a hearing next month to determine if Backman violated his probation on the DUI charge. He served a day in jail and the rest of the one-year sentence was suspended on condition that he commit no new crimes.The judge's order stems from the 2001 fight in Prineville. Backman has also had financial problems, filing for bankruptcy several years ago.Backman spent one year in the Diamondbacks' organization, working at Class-A Lancaster last season, when he was Sporting News' minor league manager of the year.The Diamondbacks' about-face embarrassed an organization making its first major decision since restructuring management and forcing out Jerry Colangelo, who headed the franchise since its started in 1998."I hope our fans will understand that we are going to make mistakes," Kendrick said, "but I hope they will learn ... that we may make mistakes but we will for certain not repeat those same mistakes. We didn't do our job this time. We will in the future."